NEW YORK (CBS 2) — Swimming is one of the summer’s most enjoyable activities, but something in the water could put your vision at risk.

As CBS 2’s Dr. Max Gomez reported Tuesday, Katie Clare was one of the victims of a painful eye infection after swimming. The 24-year-old said the summer caused her nothing but pain.

“I was just so upset,” Clare said. “I mean, I couldn’t – I wasn’t sleeping. I was just miserable.”

She said the infection eventually ended up blurring her vision.

“Really terrifying, really terrifying,” Clare said. “One of the first things the doctor said was, ‘You’re going to lose your eye if you don’t take care of this right now.’”

Clare’s infection led to a corneal ulcer — a sore on the clear tissue at the front of the eye.

And the cause?

“I swam in a pool with my contact lenses — never would have thought,” Clare said, “and I think the worst part is that I was just never told not to do that. It was, I was never told.”

Few people realize there are health risks associated with swimming in your contact lenses, Gomez reported.

“Water is very dangerous,” said Dr. Kristin Hammersmith of Wills Eye Hospital. “It has a lot of pathogens.”

There are a number of pathogenic bacteria found in lakes, ponds, swimming pools, and even the ocean.

Clare’s infection was caused by a parasite called Acanthamoeba, which can thrive in such waters, Gomez reported.

Hammersmith said such infections are on the rise this time of year, and anyone is at risk. But they are most common in people who wear the same contact lenses for too long.

The contact lenses can harbor the bacteria or other parasites where they will grow and eventually penetrate the eye.

“We see a lot more corneal infections, and they can be very serious. They can be very serious. They can be very painful,” Hammersmith said. “They can reduce vision, and even cause patients to lose their vision and need surgery.”

Traditional medications, including antibiotics, were only marginally successful for Clare. As a result, she ended up having a cornea transplant to help restore her vision.

“It’s already been two surgeries. I probably have a couple more ahead of me,” Clare said. “It’s, it’s a lot to deal with.”

To protect yourself, experts advise that you wear goggles when swimming, and never swim or shower in your lenses.

If you are an avid swimmer, doctors recommend prescription swim goggles.